JP5327632B2 - Earthquake damage prediction method, earthquake damage prediction system, and earthquake damage prediction chart for foundation structures - Google Patents

Description

  The present invention relates to an earthquake damage prediction method, an earthquake damage prediction system, and an earthquake damage prediction chart for foundation structures such as pile foundations.

  Conventionally, in the assessment of earthquake damage at facilities, fragility, which is a function of seismic intensity, has been used, and so far, not only buildings but also infrastructure structures such as piers and life of buried pipes, etc. Many fragility models have been developed for line structures (see, for example, Non-Patent Documents 1 to 4).

  However, with regard to earthquake damage to the foundation structure due to ground deformation, which is the primary cause of damage, since there is less past earthquake damage data than in the case of buildings, etc. A model has not been proposed. For this reason, predictive evaluation of earthquake damage to foundation structures often relies on expert experience.

“Evaluation method of building damage during an earthquake”, Hiromitsu Okubo, Nobuo Matsui, Masaki Takeda, Morimasa Goto, Abstracts of Annual Conference of Architectural Institute of Japan, 17-18, 2003. “Earthquake Risk Display of Existing RC Buildings Using Seismic Diagnosis Results”, Yasuhiro Hayashi, Yoshiyuki Suzuki, Junichi Miyakoshi, Motoshi Watanabe, Proc. 2, 235-242, 2000.11 “Statistical Analysis of Fragility Curves, Proc. Of Asian-Pacific Symposium on Structural Reliability and its Applications, Taipei, Taiwan, R.O.C., 1-18, 1999.2 "Two-stage evaluation model of functional life risks of supply lifelines based on seismic intensity information", Nororo Nojima, Shinta Sugito, Yasuo Suzuki, Hiroshi Ishikawa, Toshihiko Okumura, JSCE Proceedings, No. 724 / I-62, 225-238, 2003.3.1

  The method of relying on the experience of the above experts can be said to be effective in predicting and assessing earthquake damage of the foundation structure, but recently, when explaining the assumed earthquake damage to the facility operator, Insufficient disclosure of information such as conditions may be pointed out. In addition, the evaluation accuracy, progress, and the like are influenced by the experience of the expert, and depending on the evaluation target, the evaluation work may take time.

  For this reason, the standard of earthquake damage of “how much damage will be caused when a foundation structure with a certain seismic performance is subjected to earthquake motion of a certain strength” without depending on the experience of the evaluator, and The development of a quantitative prediction method has been desired.

  The present invention has been made in view of the above, and provides an earthquake damage prediction method, an earthquake damage prediction system, and an earthquake damage prediction chart of a foundation structure capable of simply and quantitatively predicting and evaluating an estimate of earthquake damage. The purpose is to do.

  In order to solve the above-mentioned problems and achieve the object, the earthquake damage prediction method for a foundation structure according to claim 1 of the present invention is an earthquake damage prediction method for predicting damage caused by an earthquake of a foundation structure provided on the ground. However, the subsidence amount obtained from the earthquake damage data of the existing foundation structure is used as a random variable, and the relationship between this subsidence amount and the probability that the foundation structure will be damaged (hereinafter referred to as the occurrence rate) is shown. While creating a curve, based on the inclination angle of the foundation structure obtained from the earthquake damage data, define at least two damage modes that indicate the damage status according to the purpose of damage prediction, and define each damage Create a fragility curve that represents the expression rate of the mode, and, for an arbitrary amount of land subsidence, the expression rate for each of the damage modes in the order based on the damage mode Create an accumulated display the cumulative probability bar chart, based on the cumulative probability bar chart created, characterized by predicting the extent of earthquake damage substructure.

  According to claim 2 of the present invention, the earthquake damage prediction method for a foundation structure according to claim 1 sets a representative damage mode according to the purpose of damage prediction based on the probability distribution of the cumulative probability bar chart. An earthquake damage prediction chart of the foundation structure for a predetermined ground subsidence amount is prepared, and the extent of earthquake damage of the foundation structure is predicted based on the earthquake damage prediction chart.

  According to claim 3 of the present invention, the earthquake damage prediction method for a foundation structure according to claim 2, wherein the ground subsidence amount is divided into predetermined sections, and the cumulative probability bar for the representative subsidence amount of each section. Create a chart, extract the probability information corresponding to the representative damage mode from each of the created cumulative probability bar charts, and create the earthquake damage prediction chart for the representative subsidence amount of each section based on this probability information It is characterized by doing.

  Moreover, the earthquake damage prediction method for a foundation structure according to claim 4 of the present invention is characterized in that, in any one of claims 1 to 3, the foundation structure is a pile foundation.

  In addition, the earthquake damage prediction system for a foundation structure according to claim 5 of the present invention is an earthquake damage prediction system for predicting damage caused by an earthquake of the foundation structure provided on the ground. A fragility curve creating means capable of creating a fragility curve indicating the relationship between the amount of ground subsidence obtained from the above and the probability of damage to the foundation structure (hereinafter referred to as the incidence); Based on the inclination angle of the foundation structure acquired from the earthquake damage data, the damage mode definition means for defining at least two damage modes representing the damage state according to the purpose of damage prediction, and the damage mode definition means A fragility curve representing the occurrence rate of each damaged mode is created by the fragility curve creating means, and it can be applied to any ground subsidence. And a bar chart creating means for creating a cumulative probability bar chart that cumulatively displays the occurrence rate for each damage mode in order based on the damage mode, and the cumulative probability bar chart created by the bar chart creating means Based on the above, the degree of earthquake damage of the foundation structure is predicted.

  The earthquake damage prediction system for a foundation structure according to claim 6 of the present invention sets the representative damage mode according to the purpose of damage prediction based on the probability distribution of the cumulative probability bar chart in claim 5 described above. A representative damage mode setting means and an earthquake damage prediction chart creating means for creating an earthquake damage prediction chart of the foundation structure for a predetermined ground subsidence amount, and based on the earthquake damage prediction chart created by the earthquake damage prediction chart creating means The feature is to predict the degree of earthquake damage of the foundation structure.

  The earthquake damage prediction system for a foundation structure according to claim 7 of the present invention is the earthquake damage prediction chart creating means according to claim 6, wherein the earthquake damage prediction chart creating means divides the ground subsidence amount into predetermined sections, and The cumulative probability bar chart is created for the representative settlement amount of each, and the probability information corresponding to the representative damage mode is extracted from each of the created cumulative probability bar charts, and based on this probability information, the representative settlement of each section is extracted. It is characterized by creating an earthquake damage prediction chart for quantity.

  Moreover, the earthquake damage prediction system for a foundation structure according to claim 8 of the present invention is characterized in that, in any one of claims 5 to 7, the foundation structure is a pile foundation.

  An earthquake damage prediction chart according to claim 9 of the present invention is the earthquake damage prediction method for a foundation structure according to any one of claims 1 to 4 or any one of claims 5 to 8. An earthquake damage prediction chart used by referring to the earthquake damage prediction system for a foundation structure as described in order to predict damage caused by an earthquake of the foundation structure, wherein a distribution of damage magnitude with respect to the amount of ground subsidence is represented by a bar chart It is characterized by that.

  The earthquake damage prediction chart according to claim 10 of the present invention is characterized in that, in claim 9 described above, the distribution of damage magnitude with respect to the amount of ground subsidence is represented by a bar chart for each type of foundation structure. And

  According to the present invention, there is provided an earthquake damage prediction method for predicting damage caused by an earthquake of a foundation structure provided on the ground, wherein the ground subsidence amount obtained from the earthquake damage data of the existing foundation structure is used as a random variable, and the ground While creating a fragility curve indicating the relationship between the amount of settlement and the probability of damage to the foundation structure (hereinafter referred to as the incidence), damage prediction is based on the inclination angle of the foundation structure obtained from the earthquake damage data. Define at least two damage modes that represent the state of damage according to the purpose of the above, create a fragility curve that represents the incidence of each of the defined damage modes, and for any amount of subsidence, A cumulative probability bar chart is created in which the incidence rate for each damage mode is cumulatively displayed in the order based on the damage mode. Stomach, so to predict the extent of the earthquake damage of the basic structure, there is an effect that it is possible to predict evaluate the measure of earthquake damage easily and quantitatively.

FIG. 1 is a procedure diagram of the earthquake damage prediction method for a foundation structure according to the present invention. FIG. 2 is an explanatory diagram of the earthquake damage prediction method for a foundation structure according to the present invention. FIG. 3 is a diagram illustrating the concept of the representative damage mode. FIG. 4 is a division diagram of subsidence amounts used for risk assessment of liquefaction determination. 5A and 5B are diagrams showing cumulative probability bar charts in the damage mode, in which FIG. 5A is a diagram in the case of a settlement amount of 7.5 cm, and FIG. FIG. 6 is a diagram illustrating an example of an earthquake damage prediction chart of a pile foundation with respect to a divided settlement amount. FIG. 7 is a block diagram of the earthquake damage prediction system for a foundation structure according to the present invention.

  Below, the examples of the earthquake damage prediction method, earthquake damage prediction system and earthquake damage prediction chart of the foundation structure according to the present invention are applied to pile foundations (foundation structures) for ready-made piles and cast-in-place concrete piles. Taking this case as an example, it will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  As shown in FIG. 1, the earthquake damage prediction method for a foundation structure according to the present invention obtains the amount of ground subsidence from previously prepared earthquake damage data of pile foundations (steps S1 and S2), and uses this as a random variable. And the fragility curve which shows the relationship between this ground subsidence amount and the probability (henceforth an expression rate) that a pile foundation receives a damage is produced (step S4).

  On the other hand, the inclination angle of the foundation structure is acquired from the earthquake damage data (step S3), and based on this inclination angle, a damage mode representing the damage state corresponding to the purpose of damage prediction is defined (step S5).

  A cumulative probability bar chart that creates a fragility curve that represents the rate of occurrence of each defined damage mode and displays the rate of occurrence for each damage mode in an order based on the damage mode for any subsidence. Create (step S6).

  An earthquake damage prediction chart is created based on the created cumulative probability bar chart. Then, the evaluator refers to the earthquake damage prediction chart to predict the degree of earthquake damage of the foundation structure (step S7).

  As described above, the present invention is provided with a method for quantitatively predicting and estimating an estimated earthquake damage from a probabilistic viewpoint by using a statistical fragility curve, and the ground motion intensity of the site. In this case, a practical chart (earthquake damage prediction chart) for predicting damage according to the assumed amount of ground subsidence is provided.

a) Concept of probabilistic damage prediction method As the basis of the probabilistic damage prediction index, a fragility curve (earthquake damage degree curve) using the land subsidence amount as a random variable is used. As a derivation method of the fragility curve, for example, it is conceivable to derive the characteristic value of the fragility model as the maximum likelihood estimator by applying the maximum likelihood method.

  FIG. 2 schematically shows a method of using the fragility curve obtained as described above. In the lower part of FIG. 2, two fragility curves indicating the boundaries of the defined damage mode are shown, and in the upper part, three cumulative probability bar charts corresponding to predetermined ground subsidence amounts are shown. .

  As shown in FIG. 2, the occurrence rate (damage rate) of each damage mode defined by the foundation inclination angle (R) is expressed by a cumulative probability bar chart accumulated in ascending order of the damage mode with respect to an arbitrary subsidence amount. be able to. Here, it is assumed that the relationship between the inclination angle (R) of the foundation and the damage mode is defined as follows, and fragility is given in accordance with the definition.

[Definition of damage mode]
・ "MINOR": 1/300> R
・ “MODERATE”: 1/300 ≦ R <1/100
・ “MAJOR”: 1/100 ≦ R
Here, this damage mode is the minimum used for determining the damage level of pile foundations (for example, “Judgment Standards for Damage Level Classification of Earthquake Buildings and Restoration Technique Guidelines” edited by Japan Building Disaster Prevention Association, 15-18, 2001). This shows a case where the basic inclination angle of the criteria (R = 1/300) is defined as a threshold value.

  Referring to the cumulative probability bar chart shown in FIG. 2, the pile foundation damage with respect to the subsidence amount is one of the probabilities given by the fragility. Of these, which damage mode is the representative damage depends on the purpose of damage prediction. In the present embodiment, as shown in FIG. 3, a case where the representative damage mode is considered for the following three types will be described.

[Representative damage mode]
(1) Damage mode with a probability of not exceeding 90% 90% of the cumulative probability is damage that does not exceed the damage mode as representative damage. In other words, since it is at most 10% that the damage mode is exceeded, this corresponds to the maximum damage in terms of probability. Subsidence is the show as an example the case of S _k in FIG. 2, "MAJOR" is expected as the maximum damage.

(2) Damage mode with 50% probability The cumulative damage probability of 50% is the average damage that does not exceed the damage mode. This means the average damage that is likely to occur. Subsidence is the show as an example the case of _{S k} in FIG. 2, "MODERATE" is expected as the average damage.

(3) Predominant damage mode The damage that has the highest probability in the cumulative probability bar chart is the representative damage. This means prevailing damage as the most likely mode, and is closely related to average damage. Subsidence is the show as an example the case of _{S k} in FIG. 2, "MODERATE" is expected as excellence damage.

  If the representative damage modes (1) to (3) above are selected according to the purpose of damage prediction, a pile foundation earthquake damage prediction chart for the estimated settlement can be created.

b) Preparation of earthquake damage prediction chart When preparing an earthquake damage prediction chart, the following two points are taken into consideration from the viewpoint of practicality.
First, damage to pile foundations is uncertain because it is caused by complex factors such as the interaction between piles and the ground. For this reason, in selecting the representative damage mode, an earthquake damage prediction chart is created using “average damage likely to occur” in (2) above, which is represented by a 50% cumulative probability.

  Secondly, the subsidence amount is appropriately classified, and the average damage mode is determined for the representative subsidence amount in the section. This is considered more appropriate for predicting damage.

  In setting the section of the settlement amount, for example, the classification of the settlement amount used for the risk evaluation at the time of liquefaction determination as shown in “Architecture Design Guidelines” of the Architectural Institute of Japan can be adopted. This is divided into five sections as shown in FIG. Here, the representative settlement amount in each section is the section median value. However, for a section of 40 cm or more, the minimum 40 cm is the representative settlement amount.

  As an example, when the representative subsidence amount is S = 7.5 cm (5 to 10 cm section) and S = 30 cm (20 to 40 cm section), the cumulative probability bar chart of damage is specifically created. (B). Such a bar chart is similarly created for the representative subsidence amount of each section, and a damage mode (probability information corresponding to the representative damage mode) with a cumulative probability of 50% is extracted from the obtained cumulative probability bar chart. Based on this, an earthquake damage prediction chart for the representative settlement of each section is created. By doing so, it is possible to obtain a practical earthquake damage prediction chart which is the original purpose.

FIG. 6 shows an earthquake damage prediction chart according to the present invention. As shown in Fig. 6, this earthquake damage prediction chart is a three-level bar chart showing the estimated average damage against the above-mentioned section settlement for three types: ready-made pile + cast-in-place pile, ready-made pile, and cast-in-place pile It is a thing. In this way, by referring to the earthquake damage prediction chart displaying the damage distribution in three stages,
It is possible to easily and quantitatively predict pile foundation earthquake damage.

  Thereby, for example, if an appropriate amount of ground subsidence can be estimated by performing liquefaction determination under the estimated seismic intensity of the site, it is possible to determine an indication of damage to the pile foundation in the hazard.

Therefore, according to the present invention, the following effects can be obtained.
(1) It is possible to easily and quantitatively predict the standard of earthquake damage of the foundation structure that had to rely on the experience value of the expert so far, without depending on the experience of the evaluator. As a result, it is possible to fulfill accountability to the business owner with a probabilistic prediction basis for various problems related to the earthquake damage assumption of facilities owned by the company.

(2) If the amount of ground subsidence can be estimated appropriately under the assumed seismic intensity, it is possible to easily estimate the earthquake damage of a facility where ground deformation is dominant even if it is not an expert. The created earthquake damage prediction chart can also be used as an effective document when examining specifications for liquefaction countermeasure work and the like.

  Further, as shown in FIG. 7, the earthquake damage prediction system 100 for a foundation structure according to the present invention includes a fragility curve creating means 10, a damage mode defining means 20, a bar chart creating means 30, and a representative damage mode setting means. 40, earthquake damage prediction chart creating means 50, control means 60 having a CPU for controlling them, and past earthquake damage data 70 stored in a memory, hard disk or the like. You may provide the input means 80 which consists of a keyboard, a mouse | mouth, etc. and the output means 90, such as a printer and a monitor.

  The fragility curve creating means 10 creates a fragility curve indicating the relationship between the ground subsidence amount and the occurrence rate by using the ground subsidence amount acquired from the earthquake damage data 70 of the existing foundation structure as a random variable.

  The damage mode definition means 20 defines at least two damage modes representing damage states according to the purpose of damage prediction based on the inclination angle of the foundation structure acquired from the earthquake damage data 70.

  The bar chart creation means 30 creates a fragility curve representing the occurrence rate of each damage mode defined by the damage mode definition means 20 by the fragility curve creation means 10, and for each damage mode for each subsidence amount. This is a cumulative probability bar chart in which the occurrence rate is cumulatively displayed in order based on the damage mode.

  In the above configuration, the evaluator can predict the degree of earthquake damage of the foundation structure with reference to the cumulative probability bar chart created by the bar chart creating means 20.

  The representative damage mode setting unit 40 sets a representative damage mode corresponding to the purpose of damage prediction based on the probability distribution of the cumulative probability bar chart.

  The earthquake damage prediction chart creation means 50 creates an earthquake damage prediction chart of the foundation structure for a predetermined amount of ground subsidence. The earthquake damage prediction chart creating means 50 divides the ground subsidence amount into predetermined sections, creates a cumulative probability bar chart for the representative subsidence amount of each section, and the probability corresponding to the representative damage mode from each of the created cumulative probability bar charts. Each information is extracted, and based on this probability information, an earthquake damage prediction chart for the representative settlement amount of each section can be created. By referring to the earthquake damage prediction chart created in this way, the evaluator can easily and quantitatively predict and evaluate the standard of earthquake damage.

  As described above, according to the present invention, there is an earthquake damage prediction method for predicting damage caused by an earthquake of a foundation structure provided on the ground, and the amount of ground subsidence obtained from the earthquake damage data of the existing foundation structure is calculated. While creating a fragility curve that shows the relationship between the amount of land subsidence and the probability that the foundation structure will be damaged (hereinafter referred to as the incidence), the inclination angle of the foundation structure obtained from the earthquake damage data Based on the above, define at least two damage modes that indicate the state of damage according to the purpose of damage prediction, create a fragility curve that represents the occurrence rate of each of the defined damage modes, and any subsidence Create a cumulative probability bar chart that cumulatively displays the expression rate for each damage mode in an order based on the damage mode with respect to the amount, and create the cumulative Based on the rate bar chart, so to predict the extent of the earthquake damage of the underlying structure, it is possible to predict evaluate the measure of earthquake damage easily and quantitatively.

  As described above, the earthquake damage prediction method, earthquake damage prediction system, and earthquake damage prediction chart of the foundation structure according to the present invention predict the earthquake damage estimate of the foundation structure simply and quantitatively without depending on the evaluator's experience. It is especially useful for predicting the earthquake damages of pile foundations for ready-made piles and cast-in-place concrete piles.

DESCRIPTION OF SYMBOLS 10 Fragility curve creation means 20 Damage mode definition means 30 Bar chart creation means 40 Representative damage mode setting means 50 Earthquake damage prediction chart creation means 60 Control means 70 Existing earthquake damage data 80 Input means 90 Output means 100 Earthquake damage of foundation structure Prediction system

Claims (10)

An earthquake damage prediction method for predicting damage caused by an earthquake in a foundation structure provided on the ground,
Using the subsidence amount obtained from the earthquake damage data of the existing foundation structure as a random variable, create a fragility curve indicating the relationship between this subsidence amount and the probability that the foundation structure will be damaged (hereinafter referred to as the incidence). On the other hand, based on the inclination angle of the foundation structure acquired from the earthquake damage data, at least two or more damage modes representing damage states according to the purpose of damage prediction are defined,
While creating a fragility curve that represents the expression rate of each of the defined damage modes, the expression rate for each damage mode is cumulatively displayed in an order based on the damage mode for any amount of land subsidence. Create a cumulative probability bar chart,
An earthquake damage prediction method for a foundation structure, wherein the degree of earthquake damage to the foundation structure is predicted based on the created cumulative probability bar chart.   Based on the probability distribution of the cumulative probability bar chart, set the representative damage mode according to the purpose of damage prediction, create the earthquake damage prediction chart of the foundation structure for the predetermined ground subsidence amount, and based on this earthquake damage prediction chart 2. The method for predicting earthquake damage of a foundation structure according to claim 1, wherein the degree of earthquake damage of the foundation structure is predicted.   The ground subsidence amount is divided into predetermined sections, the cumulative probability bar chart is created for the representative subsidence amount of each section, and probability information corresponding to the representative damage mode is extracted from each of the created cumulative probability bar charts. 3. The earthquake damage prediction method for a foundation structure according to claim 2, wherein the earthquake damage prediction chart for the representative settlement amount of each section is created based on the probability information.   The earthquake damage prediction method for a foundation structure according to any one of claims 1 to 3, wherein the foundation structure is a pile foundation. An earthquake damage prediction system for predicting damage caused by earthquakes in the foundation structure installed on the ground,
Using the subsidence amount obtained from the earthquake damage data of the existing foundation structure as a random variable, it is possible to create a fragility curve that indicates the relationship between this subsidence amount and the probability that the foundation structure will be damaged (hereinafter referred to as the incidence). Fragility curve creation means,
Damage mode defining means for defining at least two damage modes representing damage states according to the purpose of damage prediction based on the inclination angle of the foundation structure acquired from the earthquake damage data;
A fragility curve representing the expression rate of each damage mode defined by the damage mode defining means is created by the fragility curve creating means, and the expression rate for each damage mode is calculated for any subsidence amount. And a bar chart creating means for creating a cumulative probability bar chart that is cumulatively displayed in order based on the damage mode,
An earthquake damage prediction system for a foundation structure, wherein the extent of earthquake damage to the foundation structure is predicted based on a cumulative probability bar chart created by the bar chart creation means.   A representative damage mode setting means for setting a representative damage mode according to the purpose of damage prediction based on the probability distribution of the cumulative probability bar chart, and an earthquake damage prediction for creating an earthquake damage prediction chart of the foundation structure for a predetermined ground subsidence amount 6. The method according to claim 5, further comprising a chart creating means, wherein the degree of earthquake damage of the foundation structure is predicted based on the earthquake damage prediction chart created by the earthquake damage prediction chart creating means. Earthquake damage prediction system for foundation structures.   The earthquake damage prediction chart creating means divides the ground subsidence amount into predetermined sections, creates the cumulative probability bar chart for the representative subsidence amount of each section, and generates the representative damage from the created cumulative probability bar chart. 7. The earthquake damage prediction of the foundation structure according to claim 6, wherein probability information corresponding to each mode is extracted, and an earthquake damage prediction chart for the representative subsidence amount of each section is created based on the probability information. system.   The earthquake damage prediction system for a foundation structure according to any one of claims 5 to 7, wherein the foundation structure is a pile foundation. The earthquake damage prediction method for the foundation structure according to any one of claims 1 to 4 or the earthquake damage prediction system for the foundation structure according to any one of claims 5 to 8 to predict damage caused by the earthquake of the foundation structure. An earthquake damage prediction chart that is used to refer to
An earthquake damage prediction chart, wherein the damage distribution with respect to the amount of land subsidence is represented by a bar chart.   The earthquake damage prediction chart according to claim 9, wherein the distribution of the magnitude of damage with respect to the amount of ground subsidence is represented by a bar chart for each form of foundation structure.

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